1. Technical Field
The disclosure generally relates to a mobile virtual private network (MVPN) system, and more particularly, to a call setup method for a MVPN and an access point apparatus thereof.
2. Description of Related Art
Most telephone calls made over mobile communication within an enterprise are made indoors. However, in recent years, mobile network providers have stopped setting up new base stations or may even remove existing base stations due to the increasing concern over our environment, which causes serious deficiency of indoor coverage and communication capacity in mobile communication.
Presently, the indoor access point apparatus technique or the femtocell technique is adopted for resolving the problem of deficient indoor coverage and communication capacity. A mobile virtual private network (MVPN) system can be adopted to deal with the situation that most telephone calls made over mobile communication within an enterprise are made indoors. The MVPN system allows a user to receive an incoming call by using his mobile phone when an internal caller dials an internal extension number of the user. However, in a conventional MVPN system, all the resources for setting up calls and providing call services (for example, the radio resources of base stations, the bandwidth resources of the backbone network, and related mobile add-ons equipments, etc) are provided by the mobile communication provider. Thus, the setup and running cost of the MVPN system is very high.